Door construction and method

ABSTRACT

A new and improved door construction and method of manufacturing same are advantageously provided. The door includes first and second formed door panels, each having an identical or substantially similar L-shaped profile defined by an elongated back portion and a relatively shorter base portion. The first and second formed door panels are placed in opposed nesting relation so that the back portions and the base portions are arranged in opposed facing relation to each other. A hollow region is thus defined by and between the first and second formed door panels. The panels are temporarily held in alignment to each other in this relationship by an adhesive, preferably through use of a suitable internal core material secured between the panels by the adhesive. The panels are thereafter permanently joined by laser welding performed along first and second seams. In particular, the first seam is formed at the abutment of the base of the first panel with the back of the second panel, and the second seam is formed at the abutment of the base of the second panel with the back of the first panel. The first seam is disposed along a first lateral edge of the door construction immediately adjacent the back portion of the second panel. The second seam is disposed along a second lateral edge of the door construction immediately adjacent the back portion of the first panel. This arrangement results in substantially uninterrupted first and second door edges defined by the base portions of the first and second L-shaped door panels.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority from and hereby expresslyincorporates by reference U.S. provisional application serial No.60/153,421 filed Sep. 10, 1999.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a new and improved doorconstruction and method of manufacturing same. More particularly, theinvention relates to a construction for a metal door that is easy tomanufacture and that results in a finished door having improved strengthand pleasing aesthetics relative to prior metal doors fabricated usingconventional techniques. The subject new door also readily facilitatesattachment of conventional hardware, such as hinges, latches and thelike to the edges thereof.

[0003] Conventional metal doors are well-known and commonly encounteredin both commercial and residential applications. These prior metal doorsare typically rised of inner and outer door panels separated on oppositelateral sides by edges that maintain the panels in parallel spacedrelation to each other. The space between the inner and outer panels maybe empty or may be filled with insulation, ballast or other suitablecore material.

[0004] Metal doors of the type described are fabricated by variousmanufacturing techniques, including mechanical attachment, lock seams,intermittent resistance welding, and continuous wire welding. Thesetechniques have been found to result in a sub-optimal doorconstructions. The current fabrication methods typically result in theformation of a longitudinally extending seam bisecting or otherwiseinterrupting each edge of the door. This seam, owing to its central orother intrusive location along the entire longitudinal extent of eachdoor edge, has been found to be unsightly, specifically at areas ofhardware attachment. Moreover, the seam renders hardware installationdifficult and less precise given that many hinges, latches and otherhardware components require placement of a fastener and/or formation ofan aperture directly through the seam region.

[0005] Furthermore, conventional welding operations have been found toform visible blemishes on a door that must be removed or disguised priorto sale and use of the door. Also, because some welding operationsresult in discontinuous weld seams, the strength of the resulting dooris compromised.

[0006] Beyond the characteristics of the resulting door, known metaldoor construction techniques have been found to be deficient. Mostnotably, the construction methods are overly time-consuming andlabor-intensive to be fully cost effective.

[0007] In light of the foregoing specifically noted deficiencies andothers, a need has been identified for an alternative metal doorconstruction and method of manufacturing same. Such construction andmethod should result in a door having opposed lateral edge regions bothfree of a central or otherwise intrusive seam so that the door exhibitsimproved aesthetics and is well-suited for ease of installation ofconventional hardware. The door should also possesses improved strengthand appearance characteristics.

SUMMARY OF THE INVENTION

[0008] In accordance with the present invention, a new and improved doorconstruction and method of manufacturing same are advantageouslyprovided. The door includes first and second formed door panels, eachhaving an identical or substantially similar L-shaped profile defined byan elongated back portion and a relatively shorter base portion. Thefirst and second formed door panels are placed in opposed nestingrelation so that the back portions and the base portions are arranged inopposed facing relation to each other. A hollow region is thus definedby and between the first and second formed door panels. The panels aretemporarily held in alignment to each other in this relationship by anadhesive, preferably through use of a suitable internal core materialsecured between the panels by the adhesive. The panels are thereafterpermanently joined by laser welding performed along first and secondseams. In particular, the first seam is formed at the abutment of thebase of the first panel with the back of the second panel, and thesecond seam is formed at the abutment of the base of the second panelwith the back of the first panel. The first seam is disposed along afirst lateral edge of the door construction immediately adjacent theback portion of the second panel. The second seam is disposed along asecond lateral edge of the door construction immediately adjacent theback portion of the first panel. This arrangement results insubstantially uninterrupted first and second door edges defined by thebase portions of the first and second L-shaped door panels.

[0009] One advantage of the invention resides in the provision of a newand improved door construction and method.

[0010] Another advantage of the invention is found in a new doorconstruction wherein the opposed edges of the door are substantiallyuninterrupted by continuously welded seams.

[0011] A further advantage of the invention is the provision of a doorconstruction where first and second door defining panels are weldedtogether along at least substantial portions of their lengths bycontinuous, uninterrupted welds.

[0012] Yet another advantage of the invention is found in a new doorconstruction that exhibits no welding blemishes incurred during themanufacturing process.

[0013] Still another advantage of the invention resides in a new andimproved door construction method that is more efficient and costeffective compared to conventional welded door construction methods.

[0014] A still further advantage of the present invention is found inthe provision of a new and improved door construction adapted to receiveall associated lock assemblies in one door panel with very closetolerances which results in an exceptionally close precision fit for alllocking hardware.

[0015] Still other benefits and advantages of the invention will becomeapparent to those of ordinary skill in the art upon reading andunderstanding the following specification.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The invention may take form in various components andarrangements of components, and various of steps and arrangements ofsteps, preferred embodiments of which are illustrated in theaccompanying drawings that form a part hereof and wherein:

[0017]FIG. 1 is a flow-chart illustrating a method of constructing adoor in accordance with the present invention;

[0018]FIG. 2 is a plan view of a door blank used in forming a door panelin accordance with the invention;

[0019]FIG. 3 is an exploded end view showing two formed door panels asthey are secured together to form a temporary door construction inaccordance with the invention;

[0020]FIG. 4 is an end view of the temporary door construction of FIG. 3as it is subjected to a laser welding process to form a doorconstruction in accordance with the invention; and,

[0021]FIG. 5 is an end view of the door construction of FIG. 4 followingcompletion of the laser welding process and insertion of optionalinterior cores.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Referring now to the FIGURES wherein the showings are forpurposes of illustrating preferred embodiments of the invention only andnot for purposes of limiting same, FIG. 1 provides an overview of a doorconstruction method contemplated by the present invention. In general,the method includes: (S1) receiving flat metal panels; (S2) fabricatingflat door blanks from the flat panels; (S3) forming the door blank tohave a substantially L-shaped profile; (S4) cleaning, degreasing, andreinforcing the formed door panels; (S5) fabricating a temporary doorconstruction from the formed door panels with adhesive; (S6) laserwelding the formed door panels of the temporary door constructiontogether to form a door construction; and, (S7) finishing the doorconstruction.

[0023] With reference also to FIGS. 2-5, implementation of the methodschematically illustrated in FIG. 1 is discussed in further detail. Flatmetal panels, preferably cold rolled or A60 galvanealed steel having athickness in the range of 0.019″-0.070″ (24 gauge-14 gauge) are receivedand fed to a press or the like to form flat door blanks 10. The doorblanks 10 may be any suitable size and shape as desired to form a doorconstruction having predetermined desired dimensional characteristics.

[0024] The door blanks 10 are then fed to a press that forms each of theblanks into a formed door panel 20 (FIG. 3). In particular, the doorblanks 10 are fed to a rotary bending press that bends each blank at theregions 12 a, 12 b, 12 c, thus resulting in a formed door panel 20. Asshown, the door blank 10 is bent approximately 90° at the regions 12 b,12 c, and crimped at the region 12 a. The formed panel 20 thus has anoverall L-shaped cross-section or profile, defined by an elongated backmember 22 and a relatively shorter base member 24 projecting outwardlyfrom the back member 22 at a first end thereof. The base member 24preferably includes an upturned foot 26 at its distal end that definesan outwardly facing surface 28 arranged parallel to the elongated backmember 22. A second end 30 of the elongated back member opposite thefirst end from which the base member 24 projects, is preferably foldedupon itself and crimped at region 12 a to ensure that the end 30 issquare and suitably formed for laser welding. The crimped end 30presents an inner face 32 that lies parallel to or otherwise conforms tothe face 28 of the foot 26.

[0025] Those of ordinary skill in the art will recognize that the baseportion 24 of a formed door panel 20 need not project at a right-anglefrom the elongated back member 22. If desired, the base member 24 mayproject from the back member 22 at an angle greater or less than 90°without departing from the overall intent or scope of the presentinvention. Such arrangement is still deemed to form an L-shaped panel 20as defined herein.

[0026] Once door panels 20 are formed as desired, they are cleaned anddegreased. If necessary or appropriate, reinforcing members, such asgussets, tapping plates, and/or the like, may be welded, adhered, orotherwise affixed to each formed door panel 20 where desired.

[0027] As illustrated in FIG. 3, two door panels 20 are arranged into adoor construction by placing the panels 20 in opposed nestingrelation—so that the elongated back members 22 thereof are disposed inopposed facing relation, and so that the base members 24 of the panels20 are likewise situated relative to each other.

[0028] More specifically, to assemble a door construction in accordancewith a preferred embodiment of the present invention, two formed panelsare abutted so that the outer surface 28 of each foot 26 contacts theface 32 of the other panel 20. Prior to abutment of the panels 20, anadhesive generally designated A (FIG. 3) is applied in the form of abead along the interior face 23 of each panel 20. A core material 80(FIG. 5) is placed between the panels 20 when they are abutted and issecured to each panel 20 by the adhesive A. This, then, causes the doorpanels 20 to be adhesively secured in the desired position relative toeach other, and to form a temporary door construction 50 (FIG. 4) havinga first seam 52 and a second seam 54. Of course, those of ordinary skillin the art will recognize that the adhesive may be applied to one orboth of the panels 20 at locations other than that specifically noted(e.g., along the faces 28 and/or 32) to secure the panels in relation toeach other prior to welding without departing from the overall scope andintent of the present invention. The temporary door construction 50 hasa length equal to the length L of the blank 10, and a width W (FIG. 4)equal to the distance between the regions 12 a,12 b of the blank 10.

[0029] With continuing reference to FIG. 4, a laser welding system 60,such as a 6000 Watt transfer flow CO₂ laser or other suitable laserwelding apparatus, is then used to permanently join the panels 20 ofdoor construction 50 along the first and second seams 52,54. Preferably,the laser weld is effected along the entire length of each seam 52,54.System 60 does not itself form a part of the present invention as suchsystems are commercially available in the marketplace.

[0030] The laser welding system 60 comprises a control system 62 thatreceives input from and provides output to an operator control panel 64.The control system 62 also provides output signals to the laser weldingheads 68 for controlling same. The operator panel 64 includes suitableinput switches, keypads or other devices 64 a for operator input ofinformation such as the gauge and type of material from which the panels20 are defined. The input devices 64 a can also be used to inputparameters such as the length L and width W of the temporary doorconstruction 50 to be welded by the system 60. The control panel 64further includes output lights, gauges, and/or displays 64 b to providethe system operator with feedback and status information on systemoperation.

[0031] Preferably, an operator need not use the control panel 64 toprovide the control system 62 with the length L and width W of thetemporary door construction 50. Instead, the system 60 preferablycomprises contact or non-contact sensors 66 of any suitable type forsensing the length L and width W of the temporary door construction 50prior to commencement of and/or during actual laser welding operations.As shown in FIG. 4, the sensors 66 input length and width informationinto the control system 62 that, in turn, outputs control signals to thelaser welding heads 68 to control operation of same.

[0032] Completion of the laser welding operation S6 results in theformation of a door construction 70 formed in accordance with thepresent invention as illustrated in FIG. 5. The first and second panels20 are integrally joined along the length of the first and second seams52,54. The door thus includes first and second lateral edges 72,74 thatare planar and uninterrupted by the seams 52,54. As noted above, it ispreferred that an insulation/core material, such as polystyrene, paperhoneycomb, urethane foam and/or glass fibers 80, be used to fill thehollow region 40 defined between the joined panels 20. The doorconstruction 70 is in condition for finishing in a conventional manner.

[0033] Typically, end caps are installed on the opposite open ends 76(only one end illustrated, the other being identical) to completely sealthe interior region 40. Also, various conventional hardware may beattached to the edges 72,74 and/or mounting locations for same mayeasily be formed in the edges. Of course, the door construction may alsobe coated and otherwise finished in a conventional manner.

[0034] The invention has been described with reference to preferredembodiments. Of course, modifications and alterations will occur toothers upon a reading and understanding of the preceding specification.It is intended that the invention be construed as including all suchmodifications and alterations.

Having thus described the preferred embodiments, what is claimed is: 1.A method of constructing a door comprising: forming a first door blankto have an L-shaped profile defined by a first base member and a firstback member, wherein said first base member projects outwardly from afirst end of said first back member; forming a second door blank to havean L-shaped profile defined by a second base member and a second backmember, wherein said second base member projects outwardly from a firstend of said second back member; arranging the first and second doorblanks in opposed nesting relation with said first base member abuttingand forming a first seam with a second end of said second back member,and with said second base member abutting and forming a second seam witha second end of said first back member so that said first and secondbase members are spaced from each other, said first and second backmembers are spaced from each other, and so that a space is defined byand between said first and second blanks; securing said first and seconddoor blanks in said opposed nesting relationship; laser welding saidfirst and second door blanks together at said first and second seams. 2.The door construction method as set forth in claim 1, wherein said stepsof forming each of said first and second door blanks comprises:receiving a first planar blank; using a press to form said first planarblank with said first base member arranged at 90° to said first backmember; receiving a second planar blank; and, using a press to form saidsecond planar blank with said second base member arranged at 90° to saidsecond back member.
 3. The door construction method as set forth inclaim 1, wherein said method further comprises: forming a first foot ona distal end of said first base member, said first foot extending awayfrom said first base member generally toward said second end of saidfirst back member and defining a first contact surface; forming a secondfoot on a distal end of said second base member, said second footextending away from said second base member generally toward said secondend of said second back member and defining a second contact surface. 4.The door construction method as set forth in claim 3, wherein said firstand second contact surfaces lie parallel to said first and second backmembers, respectively.
 5. The door construction method as set forth inclaim 3, further comprising: folding and crimping said first back memberupon itself at said second end so that an inner face of said crimpedsecond end of said first back member defines a third contact surface;and, folding and crimping said second back member upon itself at saidsecond end so that an inner face of said crimped second end of saidsecond back member defines a fourth contact surface, wherein said firstseam is defined by the abutment of said first and fourth contactsurfaces and said second seam is defined by the abutment of said secondand third contact surfaces.
 6. The door construction method as set forthin claim 5, wherein said step of securing said first and second doorblanks comprises: applying a bead of adhesive on inner surfaces of saidfirst and second back members and adhering each of said first and secondback members to opposite faces of a common core member located betweensaid first and second back members.
 7. The door construction method asset forth in claim 6, wherein said step of laser welding said first andsecond door blanks together comprises forming first and secondcontinuous welds that are located at and extend respectively coextensivewith said first and second seams, respectively.
 8. The door constructionmethod as set forth in claim 5, further comprising: at least partiallyfilling said space defined between said first and second door blankswith a core.
 9. The door construction method as set forth in claim 8,wherein said step of at least partially filling said space comprisesfilling said space with at least one of polystyrene foam, paperhoneycomb, urethane foam, and glass fibers.
 10. The door constructionmethod as set forth in claim 9, further comprising: closing open firstand second ends of said door construction with first and second endcaps.
 11. A door construction comprising: first and second door blankseach having a length, a width, and each defining an L-shaped profilecomprising: (i) a back member; and, (ii) a base member projectingoutwardly away from said back member, said first and second door blanksarranged and fixedly secured together opposed nesting relation with saidbase member of each of said first and second blanks abutting said backmember of the other of said first and second blanks to define respectivefirst and second seams, said first and second base members definingopposite lateral edges of said door construction.
 12. The doorconstruction as set forth in claim 11, wherein said opposite lateraledges are planar.
 13. The door construction as set forth in claim 11,wherein said first and second blanks are fixedly secured together byrespective first and second welds located at said first and secondseams.
 14. The door construction as set forth in claim 13, wherein saidfirst and second welds are continuous and uninterrupted and arecoextensive with the first and second seams.
 15. The door constructionas set forth in claim 11, wherein a space is defined between said firstand second blanks, and wherein said door construction further comprisesa core member comprising at least one of polystyrene foam, paperhoneycomb, urethane foam, and glass fibers located in said space. 16.The door construction as set forth in claim 15, wherein both said firstand second blanks are adhesively secured to said core member.
 17. Thedoor construction as set forth in claim 13, wherein: said first blank,at a distal end of said base member, defines a foot including a firstcontact surface oriented outwardly away from said back member of saidfirst blank; said first blank, at a second end of said back memberspaced from said base member, is folded and crimped upon itself so as todefine a second contact surface; said second blank, at a distal end ofsaid base member, defines a foot including a third contact surfaceoriented outwardly away from said back member of said second blank; saidsecond blank, at a second end of said back member spaced from said basemember, is folded and crimped upon itself so as to define a fourthcontact surface; said first seam is defined at an abutment of said firstand fourth contact surfaces; and, said second seam is defined at anabutment of said second and third contact surfaces.
 18. The doorconstruction as set forth in claim 16, wherein said first, second,third, and fourth contact surfaces are all parallel to each other and tosaid respective back members of said first and second blanks.